Manufacture of calcium hypochlorite



7 wet product such as a Patented May 2], 1929.

UNITED STATES PATENT OFFICE.-

JESSE A, GUYER, OF LA SALLE, NEW YORK, ASSIGNOR TO THE IA'JJHIESONALKALI WORKS, INC., OF NEW YORK, N. Y., A

CORPORATION 01 VIRGINIA.

-MAN'UZEAQZ'I.URI? OF CALCIUM HYPOCHI|ORITE.

No Drawing.

This invention relates to improvements in the production of calciumhypochlorite products. In the manufacture of calcium hypochloriteproducts, it is usually desirable to make products that are free fromcalcium chloride or contain but a minimum of calcium chloride forseveral reasons.- In particular, calcium chloride is very hygroscopicand makes the products diflicult to dry when pres.- ent in substantialamount, and this same property of calcium chloride also tends tomake theproduct unstable when it contains calcium chloride in substantialamount. The present invention provides a method of freeing calciumhypochlorite products from such calcium chloride as they may contain.

According to the present invention, the calcium hypochlorite productcontaining calcium chloride is treated with a caustic alkali such] ascaustic soda in amount chemically equivalent to the calcium chloridecontent of the product. Calcium chloride present may thus be convertedto 'calcium hydroxide with the formation of alkali chloride. The alkalichlorides such as sodium chloride and lime, or calcium hydroxide, aparently do not adversely affect the stability of calcium hypochlorite,and likewise these substances are not hygroscopic at least not to suchanextent drying the product.

as to involve difiiculties Moreover, once the product is dried thesesubstances do not tend to absorb water.

The process of the invention is applicable to dry products, or toslurries and filter cakes, or the like. In carrying out the invention,an amount of caustic alkali approximately equivalent to the calciumchloride present is thoroughly mixed with the calcium hypochloriteproduct in the presence of sutiicient water to enable the mixture to bethorou hly mixed. In treating a dry product, all the water necessarymust, be added, and in treating a slurry or an undried ter or press cakeallowance is made for the water already present It is particularly addedto permit adequate mixture. -1ng treatment with'caustic alkali, theresult-- Application filed August 4, 1928. Serial No. 127,172.

advantageous to carry out the operation of the present invention at astage in the roduction of the calcium hypochlorite product such that nowater or but a minimum of water need be added. The caustic alkali may besuppliedas such and dissolved during mixture with the calciumhypochlorite 7 product or 1t. may be supplied as a solution. -Thecaustic alkali may, for example, be supplied dissolved in the water, orpart of the water,

Following slurry or paste may be dried either with or without pressing.To illustrate: 200 pounds of a calcium hypochlorite-calcium chloridefilter cake containing about pounds of calcium chloride is treated with14.4 pounds of sodium hydroxide and suflicient water to facilitatemixing, for example,

After addition of the SOdlllIIl h droxide and water, the mixture isthorough y mixed and subsequently dried.

I claim.

1.\An improved method of eliminating calcium chloride from calciumhypochlorite products" containing the same which com- 11 ounds of water.

prises treating the calcium hypochlorite prodnot containing calciumchloride with caustic alkali in the presence of water.

2.An improved method of eliminating calcium chloride from calciumhypochlorite products containing the same which comprises treating thecalcium hypochlorite product containingcalciumchloride with sodiumhydroxide in the presence of water.

3. An improved method of eliminating cal-.

cium chloride from calcium hypochlorite products containing the samewhich comprises treating the calcium hypochlorite product containingcalcium chloride with an amount of caustic alkali equivalent to theamount ofcalcium chloride present in the presence of water.

In testimony whereof I aflix my signature.

JESSE A. GUYER.

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